Elongated medical device with functional distal end

ABSTRACT

An elongate medical device that may be used for performing medical procedures on a patient is provided. This elongate medical device may include a first member having a distal end, an outer surface, and a first lumen, where the first member may have an elongated configuration such that the length of the first member is at least ten times greater than the width of the first member. The elongate medical device may also have a second member positioned within the first member and a hood stop. The hood stop in this device may be positioned within the first member and may have a distal region and a shoulder region where the shoulder region may be configured to limit the travel of the first member or the second member past the hood stop.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 10/844,425,filed May 13, 2004, which is a Continuation of application Ser. No.10/379,591, filed Mar. 6, 2003, which is a Continuation of applicationSer. No. 09/695,527, filed Oct. 24, 2000, both of which are includedherein in their entirety by reference.

FIELD OF THE INVENTION

The claims of the present invention are directed towards medicaldevices. More specifically, the claims of the present invention arerelated to catheters, endoscopes, and other medical devices withfunction distal ends that may be used to perform medical procedureswithin the body of a patient.

BACKGROUND OF THE INVENTION

A number of techniques are available for treating cardiovascular diseasesuch as cardiovascular bypass surgery, coronary angioplasty, coronaryatherectomy, and stent placement. These techniques are generallyperformed to bypass or open lesions in coronary vessels to restorepatency and increase blood flow to the heart muscle. In some patients,the number of lesions are so great, or the locations so remote in thecoronary vasculature, that restoring coronary artery blood flow to theheart is difficult. Transmyocardial revascularization (TMR), also knownas percutaneous myocardial revascularization (PMR), has been developedas an alternative to these techniques which are directed to bypassing orremoving lesions.

Heart muscle may be classified as healthy, hibernating, and “dead.” Deadtissue is not dead but is scarred, no longer contracting, and no longercapable of contracting even if adequately supplied with blood.Hibernating tissue is not contracting muscle tissue but is capable ofcontracting again, provided it is once more adequately supplied withblood. PMR is performed by wounding the myocardium of the heart, oftenforming and leaving patent holes, and sometimes injecting angiogenicsubstances in the process.

PMR was inspired in part by observations that reptilian hearts arelargely supplied by blood directly from within the heart chambers. Incontrast, mammalian hearts are supplied by blood pumped from the heart,through the aorta, and back to the heart muscle through the coronaryarteries. Positive results have been observed in some patients receivingPMR treatments. The positive results may be due in part to blood beingperfused into the myocardium from within the heart chambers throughholes into the myocardium. The positive results are believed to be duein part to a wound healing response of the myocardium which includesformation of new blood vessels in the heart wall, which are believed toconnect with the heart chamber interior and/or other coronary bloodvessels. The PMR procedure can include cutting into the myocardium withtherapeutic tips or burning holes with therapeutic tips having laser orradio-frequency current tips. PMR therapeutic tips can also be used toinject angiogenic substances such as growth factors or genes selected toinduce angiogenesis.

The PMR procedure generally involves insertion of a therapeutic tip suchas a sharp cutting tip into the heart chamber or chambers selected fortreatment. The cutting tip and associated inner shaft can be guided intothe chamber within a guide catheter, which may have been inserted intothe vasculature a long distance from the heart. After the inner shaftdistal end exits the guide catheter, the cutting tip is preferablysteered to several positions for formation of several holes in a patternacross the endocardium. In order to steer the inner shaft and cuttingtip, an outer shaft or tube is sometimes disposed coaxially about theinner shaft and within the guide catheter. The outer tube can havestructural features at the distal end for bending to various angles toreach various locations in the heart wall. The outer tube and innershaft can be cooperatively advanced to bring the cutting tip intocontact with the heart wall.

To allow passage through the guide catheter, the outer tube should havea sufficiently small radial or transverse profile over its length. Aswith many catheter devices, a small profile is desirable to allowpassage through tortuous and narrow vessels. At the outer tube distalend, however, a small profile can also mean a small profile presented tothe heart wall when inserting a cutting tip. It may be desirable tobring the outer tube very close or even into contact with the heartwall. While inserting a cutting tip into the heart wall may bedesirable, inserting the larger outer tube distal end into the heartwall may be undesirable.

What is desirable is an improved guide device for steering inner shaftcutting tips into position within the heart myocardium. The improvedguide device would preferably include a distal end having a smallprofile for passage through a guide catheter, yet having a largerprofile for presentation to the heart inner wall to limit undesirablepenetration by the guide device distal end.

SUMMARY OF THE INVENTION

The present invention includes devices for performing percutaneousmyocardial revascularization (PMR) that can lessen the likelihood of ashaft distal end penetrating undesirably into the myocardium. In oneapplication, PMR devices are used to penetrate the endocardium andmyocardium to a controlled depth. One group of devices according to thepresent invention includes an inner shaft having a therapeutic tip, forexample, a distal cutting tip. The inner shaft can be disposed within anouter tube or shaft lumen, and the outer shaft can be disposed withinthe lumen of a guide catheter. Preferably, the myocardium is penetratedby the cutting tip of the inner shaft but not by any larger profileouter shafts or tubes disposed about the inner shaft. The outer shaftdistal region preferably has a first configuration having a small radialextent or profile allowing disposition of the outer shaft within a smallguide catheter. The outer shaft distal region preferably also has asecond configuration having a larger radial extent or profile forpresentation against the endocardium. While having the larger profile,the outer tube distal end has increased resistance to penetrating theheart wall. The larger surface presented to the heart wall while in theradially expanded position forms a more atraumatic distal end for theouter tube distal end.

The outer tube distal end can have an atraumatic distal hood or tip thatis formed of an elastic material that can be benignly forced against anobstacle such as the heart chamber inner wall, the endocardium. Theatraumatic hood allows passage of the therapeutic tip therethrough tocontact the heart wall. The atraumatic hood preferably has asufficiently small profile so as to fit within an enclosing guidecatheter in a first configuration. In one embodiment, the atraumatichood is sufficiently elastic to longitudinally foreshorten and radiallyexpand to attain a larger profile or radial extent when forced againstthe endocardium. The radially enlarged hood presents a larger transversesurface area to the heart wall and inhibits penetration of the heartwall by the outer shaft distal end. In one embodiment, the atraumatichood has a bulbous shape and has a distal-most orifice for receiving thecutting tip of a slidably disposed inner therapeutic shaft.

One outer shaft atraumatic tip includes a distally disposed elasticmember having a first, constrained configuration, and a second,unconstrained configuration. In a constrained configuration, which mayoccur when the tip is constrained within an enclosing guide catheter,the tip has a radial extent or profile that fits within the guidecatheter. In an unconstrained configuration, the tip can expand to alarger radial extent or profile, where the radial extent is preferablylarger than the outer diameter of the guide catheter. One atraumatic tipincludes an elastomeric disk or washer transversely disposed to thelongitudinal axis of the catheter. Another atraumatic tip includesseveral radially disposed segments or arms. In use, the atraumatic tipcan expand radially outward when advanced from a guide catheter, and canradially contract when retracted back within the guide catheter.

Another outer shaft atraumatic distal end or stop includes a springwound about the outside of the outer shaft distal region. The springpreferably has a constrained configuration when contained within anenclosing guide catheter. When advanced distally from the guidecatheter, the spring preferably expands radially to a second,unconstrained configuration having a larger profile. The larger profilecan present a hindrance to penetration of the endocardium by the distalend of the outer shaft. After use of any inner therapeutic shaft, theouter shaft can be retracted within a guide catheter, again constrainingthe distal spring and reducing the radial extent. In one embodiment, thespring is formed as a helical coil. In another embodiment, the spring isformed as a ribbon or clock spring disposed about a relatively shortlength of the outer shaft.

One device outer shaft includes an atraumatic distal region formed as aninflatable member having a small, uninflated profile and a large,inflated profile. The shaft can include an inflation lumen and theinflatable member can include an inflatable balloon having an interiorin fluid communication with the inflation lumen. The distal inflatablemember can be inserted uninflated within a guide catheter for deliveryto a target site such as the endocardium. After advancing the distalinflatable member from a guide catheter, inflation fluid can be suppliedthrough the inflation lumen and into the inflatable member, therebyincreasing the radial extent of the inflatable member. The inflatedmember or balloon can present a larger distal transverse surface area,which presents an inhibition to penetration of the endocardium by theouter shaft distal end. One device has a dual lumen shaft withside-by-side lumens. Another device has an inflation lumen coaxiallydisposed about an inner lumen which can be used for delivery of atherapeutic inner shaft.

One device has a distal cross member having a first, transverseorientation, and a second, more longitudinal orientation. The crossmember is preferably pivotally mounted to a distal-most portion of theouter tube. The cross member can have a first arm for attachment to anelongate manipulation member and a second, opposite arm having anopening for allowing passage of a therapeutic inner shaft through thetransversely disposed cross member. In one embodiment, the cross memberis biased to remain in a substantially transverse orientation to thelongitudinal axis of the outer tube. In one embodiment, the attachedcross member arm can be either pushed or pulled with the elongatemanipulation member. In some embodiments the elongate manipulationmember is capable of effectively pulling the cross member to atransverse position, but not of pushing the cross member arm to asmaller profile, more longitudinal orientation. In other embodiments,the elongate manipulation member is capable of both pushing and pullingthe cross member between small and large profile orientations.

In yet another embodiment, the outer tube has distally disposed wings orfins having a first, closed position, and a second, open position. Inthe closed position, the wings can lie closely about the outer tubedistal region outer walls, presenting a small transverse profile. In theopen position, the wings can extend radially outward, presenting a largetransverse profile. The wings can be biased to expand to the largerprofile configuration when unconstrained by a guide catheter. In oneembodiment, the wings are formed of a shape memory material, for exampleNitinol, and expand to the larger profile configuration when warmed tobody temperature. In use, the wings expand to present a large profile tothe endocardium or other surface. The wings can be forced to contractwhen the outer shaft distal end is retracted within a guide catheterhaving a smaller inside diameter than the radial extent of the distalwings.

In still another embodiment, the outer tube has a distal region whichcan be followed distally by a distal end which can be terminated moredistally by a distal-most portion. The distal end can include an outertube wall region having several longitudinally disposed slits or slotsdefining wing regions therebetween. The wing regions can includepreferential folding locations. An inner tube or shaft can be slidablyand coaxially disposed within the outer tube and secured to the outertube distal-most portion. The PMR device having the inner and outertubes can be distally advanced from a guide catheter and the inner tubemoved proximally relative to the outer tube, thereby applying a proximalpulling force on the outer tube distal-most portion. The applied forcecan force the longitudinal wings between the longitudinal slots tobuckle and splay radially outward, longitudinally foreshortening theouter tube distal end in the process. The radially outwardly splayedwings can present a larger radial extent or profile to the endocardiumand inhibit penetration of the endocardium by the outer tube. After use,the inner tube can be advanced relative to the reduced profile deviceand retracted within a guide catheter.

In another embodiment a therapeutic catheter includes an outer tubehaving a distal region, a distal end, a tube wall, and a first lumenwithin the outer tube. The outer tube distal end is preferablysufficiently sharp to penetrate into the endocardium. A stop can bedisposed within the outer tube, defining a smaller inside diameterregion in a proximal portion of the outer tube distal region. A plugdisposed within the outer tube first lumen distal region preferably hasa maximum outer dimension too large to allow proximal movement past thestop. When the sharp distal end penetrates into the myocardium, thepenetration is limited by the myocardium contacting the plug, which canin turn be contacting the stop or shoulder. The stop can be an annularstop, defined by an integrally formed annular stop in one embodiment andby the distal end of an inserted inner tube in another embodiment.

In one therapeutic catheter for increasing myocardial blood perfusion,the outer tube wall has at least one substance delivery lumen disposedwithin and at least one injection port disposed near the outer tubedistal end. In another therapeutic catheter an inner tube has asubstance delivery lumen and a distal end, the inner tube being disposedwithin the outer tube. A plug having a lumen therethrough for receivingthe inner tube can be slidably disposed within the outer tube, such thatthe inner tube distal end forms a distal shoulder for limiting proximaltravel of the plug. In one embodiment, the inner tube distal end issufficiently sharp to penetrate into the myocardium and extends distallypast the plug when the plug abuts the shoulder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cutaway, perspective view of a human heart having a PMRtherapeutic tip catheter disposed within a guide catheter in the leftventricle;

FIG. 2 is fragmentary, longitudinal, cutaway view of a PMR device havingan outer tube and an inner therapeutic shaft with therapeutic tipdisposed therein;

FIG. 3 is a fragmentary, longitudinal cross-sectional view of a PMRdevice extending from a guide catheter and having an elasticallyradially expandable atraumatic tip bonded to the PMR device outer tube;

FIG. 4 is a fragmentary, longitudinal cross-sectional view of the deviceof FIG. 3 forced against the endocardium, with the inner shaftpenetrating the myocardium and the atraumatic tip radially expanded;

FIG. 5 is a fragmentary, longitudinal cross-sectional view of a PMRdevice extending from a guide catheter and having an elasticallyradially expandable atraumatic tip bonded to the outside of PMR deviceouter tube;

FIG. 6 is a fragmentary, longitudinal cross-sectional view of a PMRdevice extending from a guide catheter and having an elasticallyradially expandable atraumatic tip bonded to the inside of the PMRdevice outer tube;

FIG. 7 is a fragmentary, longitudinal cross-sectional view of a PMRdevice disposed within a guide catheter and having an elasticallyradially expandable atraumatic distal flange constrained within theguide catheter;

FIG. 8 is a fragmentary, longitudinal cross-sectional view of the PMRdevice of FIG. 7 extending from within the guide catheter and having theexpandable atraumatic distal flange radially extended;

FIG. 9 is a fragmentary, longitudinal cross-sectional view of the PMRdevice of FIG. 7 retracted within the guide catheter and having theatraumatic distal flange radially constrained within the guide catheter;

FIG. 10 is an end view of the PMR device atraumatic distal flange ofFIG. 8;

FIG. 11 is an end view of a PMR device atraumatic distal flange havingradial slits;

FIG. 12 is an end view of a PMR device atraumatic distal flange havingradial arm segments;

FIG. 13 is a fragmentary, longitudinal cross-sectional view of a PMRdevice outer tube disposed within a guide catheter and having a radiallyexpandable distal spring constrained within the guide catheter;

FIG. 14 is a fragmentary, longitudinal cutaway view of the PMR deviceouter tube of FIG. 13 extending from the guide catheter and having thespring radially expanded;

FIG. 15 is an end view of a PMR device outer tube having a ribbon springwound around the outer tube;

FIG. 16 is a fragmentary, longitudinal cross-sectional view of a PMRdevice outer tube having dual lumens and having a distal inflatableatraumatic tip;

FIG. 17 is a fragmentary, longitudinal cross-sectional view of a PMRdevice outer tube having coaxial lumens and having a distal inflatableatraumatic tip in an inflated configuration;

FIG. 18 is a fragmentary, longitudinal side view of a PMR device havinga distal, atraumatic pivotally mounted cross member, with a manipulationmember drawn in phantom within the PMR device outer tube;

FIG. 19 is a fragmentary, longitudinal cross-sectional view of the PMRdevice of FIG. 18 having the distal cross member in a transverseposition;

FIG. 20 is a fragmentary, longitudinal, cross-sectional view of a PMRdevice outer tube having a distal, atraumatic, pivotally mounted andoffset cross member;

FIG. 21 is a fragmentary, top view of one possible offset mounting forthe cross member of FIG. 21;

FIG. 22 is an end view of the outer tube of FIG. 19, with the crossmember in a transverse position;

FIG. 23 is a fragmentary, perspective view of a PMR device outer tubehaving expandable distal wings in a contracted configuration;

FIG. 24 is an end view of the wings of the device in FIG. 23;

FIG. 25 is an end view of the wings of the device in FIG. 23 in anexpanded configuration;

FIG. 26 is a fragmentary, perspective view of a PMR device having aslidable, coaxially disposed inner tube within an outer tube having adistal end with longitudinal slits;

FIG. 27 is a fragmentary, perspective view of the outer tube of thedevice of FIG. 26 having the inner tube retracted and the distal endexpanded to form an atraumatic tip;

FIG. 28 is an end view of the outer tube of FIG. 27 in the expandedconfiguration;

FIG. 29 is a fragmentary, longitudinal cross-sectional view of a PMRdevice including an inner tube, an outer tube having a lumen within thewall with a sharp distal end serving as a delivery needle, and a hoodstop, the sharp distal end shown abutting the endocardium;

FIG. 30 is a fragmentary, longitudinal cross-sectional view of the PMRdevice of FIG. 29, the sharp distal end shown penetrating theendocardium up to the hood stop now abutting the inner tube distal end;

FIG. 31 is an end view of the PMR device of FIG. 29, illustrating thehood stop within the outer tube, with injection holes shown in the outertube distal end;

FIG. 32 is a fragmentary, longitudinal cross-sectional view of a PMRdevice including an inner tube having a delivery lumen within, an outertube having a lumen within the wall with a sharp distal end serving as apenetrating needle, and a hood stop, the sharp distal end shown abuttingthe endocardium;

FIG. 33 is a fragmentary, longitudinal cross-sectional view of the PMRdevice of FIG. 32, the sharp distal end shown penetrating theendocardium up to the hood stop now abutting an inner shoulder withinthe outer tube;

FIG. 34 is a fragmentary, longitudinal cross-sectional view of a PMRdevice inner shaft having a flexible atraumatic flange stop, illustratedafter being distally extended from a guide catheter;

FIG. 35 is a fragmentary, longitudinal cross-sectional view of a PMRdevice inner shaft having a flexible atraumatic bulbous hood stop,illustrated after being distally extended from a guide catheter;

FIG. 35 is a fragmentary, longitudinal cross-sectional view of a PMRdevice inner shaft having an expandable atraumatic spring stop,illustrated prior to being distally extended from a guide catheter; and

FIG. 36 is a fragmentary, longitudinal cross-sectional view of a PMRdevice within a guide catheter.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a human heart 40 having a guide catheter 50 insertedthrough the aortic arch 42 and into the left ventricle 44. Guidecatheter 50 is shown having a therapeutic catheter 52 extendingtherethrough terminating in a therapeutic catheter therapeutic tip 54.Therapeutic tip 54 can be used to form a plurality of holes 46 in leftventricle wall 48. Therapeutic tip 54 can be used to form holes in orderto stimulate a healing, response as well as to inject angiogenicsubstances such as VEGF and other factors well-known in the art. As canbe seen from inspection of FIG. 1, the depth of holes 46 in leftventricle wall 48 are important as the holes should optimally notpenetrate through the entire wall thickness of the myocardium. Asfurther explained below, therapeutic catheter 52 is often not directlydisposed within guide catheter 50. In particular, therapeutic catheter52 may be disposed within an enclosing outer tube coaxially disposedbetween therapeutic catheter 52 and guide catheter 50.

FIG. 2 illustrates generally a PMR device 60, including a distal end 63and a distal portion 62 having an outer tube 64 having a lumen 65therein. Device 60 is an example of a PMR device suitable for inclusionof the present invention. In particular, the distal profile of device 60may be configurably expanded by incorporating various embodiments of thepresent invention. A second, inner tube or shaft 66 is disposed withinlumen 65 extending to a therapeutic tip region 70 terminating in asharp, cutting end 72 in the embodiment illustrated. Inner tube 66 maybe slidably disposed within an outer tube 64. The embodiment illustratedfurther includes a tip 68 terminating outer tube 64. Inner tube 66 maybe formed of a hypotube material and may include a swage collar 74 tolimit travel of inner shaft 66. As further discussed below, outer tubedistal end 63 and/or distal tip may have the profile or radical extentconfigurably increased.

FIG. 3 illustrates a device 100 including a guide catheter 104 having aPMR device 105 disposed therein. As can be seen from inspection of FIG.2, PMR device 105 has a maximum relaxed outer diameter of D2, which maybe compared to the inside diameter of guide catheter 104, D1. Therelatively small outer diameter or profile of device 105 allows thedevice to fit within guide catheter 104. Device 105 includes an outerwall or tube 102 and a distal region 106. Distal region 106 includes anouter wall 107 bonded at 108 to outer tube 102. An inner shaft ortherapeutic catheter 112 is disposed within a lumen 113 within outertube 102. Therapeutic catheter 112 terminates distally in a therapeuticcatheter therapeutic tip 114. Therapeutic tip 114 may have a sharpcutting end and can include means for injecting substances into theheart wall. In one embodiment, inner shaft 112 is a tube having a lumentherethrough. Therapeutic catheter 112 may be seen to extend through abrush or flange region 110. Distal region 106 terminates distally in adistal orifice 116. As can be seen from inspection of FIG. 3, the wallthickness of distal region 106 is thinner distally than proximally. Insome embodiments, distal orifice 116 is not formed until the distal-mostregion of distal region 106 is perforated by therapeutic tip 114. Thisperforation can occur as the result of advancing a slidably disposedcutting tip through the distal-most region and/or by pressing thedistal-most region against an obstacle such as the heart wall.

FIG. 4 illustrates device 105 disposed against a portion of the heartwall 117. Therapeutic tip 114 may be seen to have penetrated well intothe heart myocardium 109. As distal region 106 is forced against theheart wall, the maximum radial extent or profile of the device may beseen to increase, as indicated at D3. FIG. 4 illustrates a configurationin which device 105 has not been fully pressed against the heart wall.As illustrated by FIG. 4, the bulbous distal region 106 is splayedradially outward by compression against the heart wall. In someembodiments, the depth of penetration of therapeutic tip 114 is limitedprimarily by the outward splaying of distal region 106. In someembodiments, therapeutic catheter 112 may be relatively fixed withinouter tube 102. In such embodiments, the travel of therapeutic tip 114into the heart wall is limited by the geometry of distal region 106.

As illustrated by FIG. 4, the outer profile presented by the compressedor splayed distal region 106 is substantially greater than the profilepresented within the guide catheter. FIG. 4 thus illustrates device 106having only a small profile while within the guide catheter and a largerprofile when presented against the heart wall, thereby presenting atravel limiting, outwardly splayed larger profile surface. Distal region106 can be formed of a polymeric material, preferably one havingsufficient elastomeric properties so as to return to the configurationillustrated in FIG. 3 after being splayed outward against the heartwall, as illustrated in FIG. 4.

FIG. 5 illustrates another embodiment device 130 in which the distalregion includes an outer distal region wall 134 disposed over theoutside of a tube wall 136 and bonded thereto at 137. As in FIG. 3,device 130 includes a brush or flange region 132 disposed within 134.FIG. 6 illustrates yet another embodiment device 140 in which the distalregion walls 144 are disposed within outer tube wall 146 and bondedthereto at 147. In the embodiment illustrated, the distal region walls144 are narrowed in throat region 142 which can serve as a brush forreceiving a therapeutic catheter tip therethrough. As can be seen frominspection of FIGS. 3-6, the distal regions of the devices are radiallyexpanded and longitudinally foreshortened by contact with the heartwall. The force of compression against the heart wall is the primarycausative factor in expanding the distal regions of the devicesradially.

FIG. 7 illustrates yet another PMR device 160 having an outer tube 166terminating in a distally disposed flange 168. Flange 168 includes anorifice 164 therethrough for receiving therapeutic catheter 66. Flange168 includes outward extent 170, illustrated as bent alongside outertube 166, within guide catheter 104. While constrained within guidecatheter 104, flange 168 has a small transverse profile.

Referring now to FIG. 8, PMR device 160 has been distally forced fromthe constraint of guide catheter 104. Outermost extent 170 of flange 168may be seen to have expanded radially. Flange 168 now has a radialextent or profile larger than the radial extent or profile of guidecatheter 104. Flange 168 may be formed of an elastomeric material suchas siliconized rubber, Tecoflex, Tecothane, or 80A Pellathane. Flange168 may be formed of soft polymers with or without radiopaque loading orcoating. In one embodiment, flange 168 includes mounting or bonding arms172 bonded to outer tube 166. When pressed against the heart wall,flange 166 can present a very large profile for reducing the likelihoodof outer tube 166 penetrating into the heart wall. After use, asillustrated FIG. 9, outer tube 166 and attached flange portion 168 canbe retracted proximally back within guide catheter 104. In thisconfiguration again, flange portion 168 has a reduced outer profile orradial extent. This allows PMR device 160 to be retracted through theguide catheter.

FIG. 10 illustrates a transverse, end view of one embodiment of PMRdevice 160, illustrating distal flange portion 168. In the embodimentillustrated, distal flange portion 168 is a substantially continuouswasher having orifice 162 therethrough. Referring now to FIG. 11, adistal flange portion is formed of a plurality of slits 180 defining aplurality of segments 182 therebetween. FIG. 12 illustrates yet anotherembodiment of a distal flange portion having a plurality of separatedarms 184 disposed about a central orifice 164. As can be seen frominspection of FIGS. 7 through 12, the expandable tip portion operates byhaving a distal flange which is biased to assume a large radial extentor profile when in the unconstrained position. When constrained by guidecatheter 104, the distal flange portion is constrained to a smallerprofile configuration.

FIG. 13 illustrates yet another PMR device 200. PMR device 200 includesan outer tube 202 for receiving a therapeutic catheter therethrough.Disposed about tube 202 is a spring 204 formed as a coil. Spring 204 isbonded or otherwise affixed to the outside of outer tube 202. In theembodiment shown, spring, 204 is formed as a spiral, helical coilconfiguration having substantially constant radial extent over thelongitudinal extent of spring 204. As can be seen from inspection ofFIG. 13, coil 204 is constrained within the inner wall of guide catheter104. FIG. 13 illustrates the configuration of spring 204 prior toadvancing outer tube 202 toward the heart wall. Referring now FIG. 14,PMR device 200 is illustrated after being advanced distally out of guidecatheter 104. Spring 204 may be seen to have expanded to a larger radialextent or profile, and to have extended distally as well. In particular,the outer profile of spring 204 may be seen to be larger than the innerand even outer diameter of guide catheter 104. By affixing the proximalportion of spring 204 to outer tube 202, a spring having a potentiallylarge outer profile may be wound onto an outer tube and constrainedwithin guide catheter 104. In the embodiment illustrated, spring 204expands radially due to the bias of the spring elements. While apreferred embodiment has a spring extending over a length of outer tubeas illustrated as a helical coil or spring, other embodiments arepossible. FIG. 15 illustrates other embodiment in which a spring 210 isaffixed to outer tube 202 and configured as a spiral-wound ribbon woundabout the outer tube. In one embodiment, spring 210 is formed in aspiral shape resembling a clock spring.

In use, after advancing spring 204 from guide catheter 104, the springwill present an enlarged distal region to prevent unwanted penetrationof the heart wall by outer tube 202. After disposing spring 204 againstthe heart wall, a therapeutic catheter tip as previously illustrated maybe advanced through tube 202 and into the heart wall. After use, spring204 can be retracted proximally back within guide catheter 104, againreducing the profile. In some embodiments, spring 204 may be woundwithin guide catheter 104 by rotating outer tube 202 while retractingouter tube 202 into guide catheter 104. In other embodiments, outer tube202 may be simply retracted into guide catheter 104. In someembodiments, designed for a single deployment of spring 204, theretraction of spring 204 into guide catheter 104 may deform the spring,reducing the elastic ability of spring 204 to expand to a large radialextent the second time. In particular, in some embodiments, after use,spring 204 may be retracted within guide catheter 104, forming anelongate very long spiral coil relative to the original relativelycompact coil.

FIG. 16 illustrates a PMR device 220, including, an outer tube 236having an internal tube wall 238 therein. Outer tube 236 includes afirst lumen 222 for receiving therapeutic catheter 66. Outer tube 236also includes a second lumen 224. The distal region of device 220includes an inflatable balloon 226 having balloon interior 228 therein.Balloon interior 228 is in fluid communication through an inflationorifice 234 through outer tube 236 and in communication with secondlumen 224 which can serve as an inflation lumen. Second or inflationlumen 224 is seen to be plugged distally by a plug 230. Balloon 226 maybe seen to be bonded at 232 to outer tube 236. In use, device 222 mayhave balloon 226 uninflated and even pulled under vacuum to fullyretract balloon 226 to a low profile configuration. Device 220 may thenbe disposed in a guide catheter. After being advanced to a location nearthe heart wall, device 220 may be advanced distally from the containingguide catheter. A suitable inflation fluid may be injected into secondlumen 224 and thereafter into balloon interior 228. Balloon 226 may beexpanded to attain a large distal profile for device 220. With a largeprofile presented, the likelihood of outer tube 236 being forcedundesirably into the heart wall is greatly reduced. Once inflated,therapeutic catheter 66 may be forced against the heart wall.

Referring now FIG. 17, another embodiment of a PMR device is illustratedin a device 260 having a tip having a distal inflatable balloon. Device260 includes inflatable balloon 227 having interior 229 affixed to anouter tube 262. Disposed within outer tube 262 is an inner tube 264,coaxially disposed within tube 262. PMR device 260 includes a firstlumen 266 for receiving a therapeutic catheter, and a second orinflation lumen 268 coaxially defined between inner tube 264 and outertube 262. Balloon 227 may be seen to be bonded at 272 to inner tube 264,and is illustrated in an inflated state.

Referring now to FIGS. 18-21, another PMR device 300 is illustratedhaving a shaft 301 having a distal region 302 and a distal end 304.Distal end 304 has a cross member 310 pivotally mounted at 312, wherepivot mount 312 is preferably transversely disposed to the longitudinalaxis of shaft 301. Cross member 310 has a first arm 311 secured to anelongate manipulation member 318. Cross member 310 has a second arm 314having an opening or passageway 316 disposed therethrough. Shaft 301 hasa first lumen 306 therethrough for receiving a therapeutic catheter anda second lumen 308 therethrough for receiving elongate cross membermanipulation member 318 within.

FIG. 19 illustrates a longitudinal wafer cut through the center ofdevice 300 and having a therapeutic inner shaft 320 disposed withinfirst lumen 306. Opening 316 in cross member second arm 314 ispositioned for receiving inner shaft 320 therethrough. As can be seenfrom inspection of FIG. 19, cross member 310 is disposed in aconfiguration oriented transversely to the longitudinal axis of deviceshaft 301. In this orientation, cross member 310 presents a profile orradial extent greater than the outside diameter of shaft 301. The largerprofile can serve to inhibit penetration of the myocardium by shaft 301.In the embodiment illustrated, a central wall portion 322 separatesfirst lumen 306 from second lumen 308. A spring or bias element 324 isaffixed to both central wall portion 322 and cross member 310 so as tobias the cross member in a substantially transverse orientation. Inembodiments having a transversely biased cross member, elongatemanipulation member 318 can be a pull wire capable of being pulled fortension, but weak in compression. In embodiments not having a transversebias for the cross member, elongate manipulation 318 is preferablysufficiently strong in compression to push the cross member to atransverse orientation. The inside diameter of second lumen 308 andelongate manipulation member 318 can be cooperatively sized to providesupport in compression for the elongate manipulation member.

FIG. 20 illustrates a PMR device 330 similar in many respects to PMRdevice 300, but having cross member 310 pivotally mounted on an offsetmember 332 and rotatably secured to a pivot member 324. Offset member332 can be formed of longitudinally oriented end members allowing crossmember 310 to lie between the end members to achieve a substantiallylongitudinal orientation. As can be seen in FIG. 21, a top view ofoffset member 324 without having cross member 310 mounted, a pair of endmembers 333 can have cross member 310 mounted on pivot pin 310 betweenthe end members. FIG. 22 illustrates a transverse cross-sectional viewshowing cross member 310 mounted about central wall 322 and havingopening 316 therethrough.

Referring now to FIG. 23, another PMR device 350 is illustrated havingan outer tube 352 having a distal end 354 and having a lumen 360therethrough which can be used to receive a therapeutic inner shaft.Several expandable members or wings 356 are secured to outer tube 352 atdistal end 354. Distal wings 356 are illustrated in a firstconfiguration having a sufficiently small profile or radial extent tofit within an enclosing guide catheter. In one embodiment, distal wings356 are formed of a shape memory material having a first, small radialextent at a lower temperature and a second, large radial extent at ahigher temperature such as body temperature. In another embodiment,distal wings 356 are formed of a material biased to expand upon releasefrom the constraining guide catheter. In some embodiments, distal wings356 are formed of a metal, for example, Nitinol. In other embodiments,distal wings 356 are formed of polymeric materials. FIG. 24 illustratesa distal end view of outer tube 352 having wings 356 in a small profileconfiguration. FIG. 25 illustrates distal wings 356 in a second, largeprofile configuration.

In use, distal wings 356 can be disposed within a constraining guidecatheter and advanced to a target site. Outer shaft 352 can be advancedfrom within the guide catheter, allowing distal wings 356 to deployradially outward. When distal end 354 is pressed against the heart wall,wings 356 can present a larger profile object to inhibit the penetrationof the distal end into the heart wall. After use, distal end 354 can beretracted back into a guide catheter. In one method, outer tube 352 isrotated as the tube is retracted within the guide catheter, urging thewings to lie close to or wrap about outer tube distal end 354. In oneembodiment, the guide catheter distal end includes an internal guidegroove or other structure to urge the wings to reform a curved shapeabout the outer tube outer wall.

Referring now to FIGS. 26-28, another PMR device 380 is illustratedhaving a shaft 381 having a distal region 382, a more distal, distal end384, and a still more distal, distal-most portion 386. Shaft 381includes a lumen 395 for receiving a shaft therethrough. Distal region384 has several longitudinal slits or slots 388 formed through the wallof outer tube 381. Slits 388 define several wings 390 therebetween. Inthe embodiment illustrated, wings 390 have a region for preferentialfolding, such as weakened area 392. Distal end 384 is designed tolongitudinally buckle under an applied force, thereby longitudinallyforeshortening the distal end and radially expanding the radial extentor profile of the distal end. The applied force can come from acompressive force of being forced against the heart wall and/or a forceapplied by a longitudinal elongate member disposed within outer tube 381and secured at the distal end to distal-most portion 386. In theembodiment illustrated, an inner tube 396 is slidably disposed withinlumen outer tube lumen 395. Inner tube 396 has a lumen 397 therethroughfor receiving a shaft with therapeutic tip. Inner tube 396 can besecured to outer tube 381 at distal-most portion 386.

FIG. 27 illustrates PMR device 380 in a radially expanded configurationin which inner tube 396 has been proximally retracted relative to outertube 381, longitudinally foreshortening and radially expanding distalend 384. FIG. 28 illustrates an end view of PMR device 380. Wings 390may be seen to be significantly radially expanded relative to theconfiguration illustrated in FIG. 26. The expanded, increased profiledistal end presents a larger transverse surface area and offers animpediment to distal end 384 penetrating the heart wall.

The outer tubes and coupled atraumatic distal tips discussed arebelieved suitable for use in limiting unwanted penetration of theendocardium while allowing disposition within a more outer tube, forexample, a guide catheter. The scope of the invention is of course notlimited to these uses. The present invention can be used as part of manydevices and in many applications where a small profile is desired in afirst configuration and a larger profile is desired in a secondconfiguration. Devices incorporating the present invention may be usedto advantage anywhere a small distal profile is desired, including somedevices used for direct passage within the body, rather than used forpassage through enclosing tubes or guide catheter.

Referring now to FIG. 29, a PMR device 400 is illustrated, having anouter tube 410 disposed about an inner tube 414 and having a plug orhood stop 420. PMR device 420 is illustrated abutting endocardium 408.Inner tube 414 has a lumen 416 therethrough and a distal end 418, whichcan serve to limit the proximal travel of hood stop 420. Outer tube 410has a distal region 404, a sharp distal tip 406, and an intermediateregion 402. Outer tube 410 has a wall having a lumen 412, the spacewithin which can serve as a therapeutic substance delivery lumen. Sharpdistal end 406 can serve as a needle for injecting a therapeuticsubstance through distal holes 428 (shown in FIG. 31). Hood stop 420includes a large outer diameter distal region 426, a shoulder region424, and a small outer diameter proximal region 422. Outer tube 410 hasan inside diameter in distal region 404 sufficiently large toaccommodate hood stop 420, with inner tube distal end 418 serving as astop or shoulder and having an inside diameter sufficiently small tolimit the proximal travel of hood stop 429. In some embodiments, distalregion 404 has a distally decreasing inside diameter, such that hoodstop 420 is precluded from exiting outer tube 410 distally. In oneembodiment, the stop or shoulder is formed by a region of decreasedinside diameter integrally formed with the outer tube, similar to outertube 442 of FIG. 30.

Referring now to FIG. 30, PMR device 400 is illustrated afterpenetrating endocardium 408. Outer tube distal end 406 has penetratedinto endocardium. 408, thereby penetrating injection holes 428 (shown inFIG. 31) into the heart wall. Penetration of outer tube distal end 406is limited by stop 420 which can now abut endocardium 408 on the distalside and abut inner tube distal end 418 on the proximal side withshoulder region 424. Outer tube wall lumen 412 can be used to inject atherapeutic substance into the heart wall through distal end 406. FIG.31 illustrates an end view of PMR device 400, illustrating injectionholes 428 in outer tube distal end 406, distal stop 420, and outer tube410. Outer tube 410 and inner tube 414 can be formed of materialspreviously discussed, for example hypotube or polymeric materials.

Referring now to FIG. 32, a PMR device 440 is illustrated, having aouter tube 442, an inner tube 456, and a plug or hood stop 470. PMRdevice 440 is illustrated abutting endocardium 408. Inner tube 456 has adistal end 458 and a delivery lumen 460 within. In some embodiments,distal end 458 is sharp and has a length intended to penetrate into theheart wall through hood stop 470. In other embodiments, distal end 458is dull and has a length intended to remain within hood stop 470 whenthe PMR device has penetrated into the heart wall. Delivery lumen 460can be used to inject or infuse a therapeutic substance. Outer tube 442includes a sharp distal tip 448, a distal region 446, and anintermediate region 444. Outer tube 442 includes a shoulder region 452disposed proximal of a larger inside diameter region 450 and distal of asmaller inside diameter region 454. Hood stop 470 includes a distallarge outer diameter region 472, an annular ring portion 471, a shoulderregion 474, and a proximal small outer diameter region 478. Hood stop470 can also include a lumen 476 extending through the stop, allowingsome penetration of inner tube distal end 458 past the distal face ofthe stop and into the heart wall, to aid in injecting a therapeuticsubstance into the heart wall. In some embodiments, distal region 446has a distally decreasing inside diameter, such that hood stop 470 isprecluded from exiting outer tube 442 distally.

Inner tube lumen 460 can be used to inject a therapeutic substance intothe heart wall past distal end 458. Outer tube 442 and inner tube 456can be formed of materials previously discussed, for example hypotube orpolymeric materials. Hood stop 470 can be formed of atraumatic polymericmaterials, previously discussed.

Referring now to FIG. 34, a PMR device 500 is illustrated disposedwithin guide catheter 104, having inner tube or shaft 66 withtherapeutic tip region 70 and terminating in cutting tip 72, asdiscussed with respect to FIG. 2. PMR device 500 also has a flange orstop 502, which can be similar to flange 168 as discussed with respectto FIGS. 7 and 8. Flange 502 can be formed of the same materialsdiscussed with respect to flange 168 of FIGS. 7 and 8. Flange 502 ispreferably formed of an elastomeric material, which contracts or isfolded back, such that the flange has a radial extent or profile smallenough to fit within guide catheter 104. Guide catheter 104 can beadvanced to be near a target site, with flange 502 folded within guidecatheter 104. Inner shaft 66 can be advanced forward relative to guidecatheter 104, thereby deploying flange 502 to an expanded state havingan increased radial extent or profile. Inner shaft 66 is preferablyfixedly attached to flange 502. As inner shaft cutting, tip 72 isadvanced into the myocardium, flange 502 can serve to limit the extentof travel into the heart wall. After use, flange 502 can be retractedinto guide catheter 104, reducing the radial extent of flange 502, andguide catheter 502 can be used further or retracted from the body.

Referring now to FIG. 35, a PMR device 520 is illustrated, advanceddistally from guide catheter 104. PMR device 520 includes inner shaft ortherapeutic catheter 112 terminating in cutting tip 114, discussedpreviously with respect to FIGS. 3 and 4. PMR device 520 includes abulbous tip or hood 530 having an outer wall 522 and a distal region 526terminating in a distal orifice 524. Outer wall 522 can be formed of thesame materials as outer wall 102 discussed with respect to FIGS. 3 and4. Bulbous tip 530 can be fixedly attached to inner shaft 112 throughflange 110 and at a bulbous tip proximal region 528. Bulbous tip 530 isillustrated as having been distally extended from guide catheter 104.

In use, cutting tip 114 can penetrate into the myocardium, with thedepth of penetration limited by bulbous tip distal region 526 expandingupon contact with the endocardium. In operation, outer wall 522 canoperate much the same as outer wall 102 illustrated in FIG. 4, expandingupon contact with the heart chamber wall. After use, bulbous tip 530 canbe retracted into guide catheter 104. In one embodiment, PMR device 520has a shorter tube enclosing the inner shaft distal region relative tothat of PMR device 100. In one embodiment, PMR device 530 has innershaft 112 directly disposed within guide catheter 104 for a majority ofthe length of inner shaft 112.

Referring now to FIG. 36, a PMR device 540 is illustrated disposedwithin guide catheter 104. PMR device 540 includes an inner shaft 542terminating in a distal therapeutic and/or cutting tip 544 havingexpandable coil 204 secured to inner shaft 542 at a fixation location543 located proximal of a cutting tip 544. Coil 204 was discussedpreviously with respect to FIGS. 13 and 14. Inner shaft 542 can beformed of similar materials as inner shaft 112 discussed with respect toFIG. 3. FIG. 36 illustrates coil 204 constrained within guide catheter104.

In use, guide catheter 204 can be advanced to near a target site, withPMR device coil 204 constrained within guide catheter 104. Inner shaft542 can be distally advanced, or guide catheter 103 proximallyretracted, freeing coil 204, allowing the coil to expand radially, asillustrated and discussed with respect to FIGS. 13 and 14. Coil 204 canact to limit the penetration of cutting tip 544 into the myocardium.After penetration into the myocardium, coil 204 can be retracted intothe guide catheter. In some methods, inner shaft 542 is rotated to aidin bringing coil 204 within guide catheter 204.

Numerous advantages of the invention covered by this document have beenset forth in the foregoing description. It will be understood, however,that this disclosure is, in many respects, only illustrative. Changesmay be made in details, particularly in matters of shape, size, andarrangement of parts without exceeding the scope of the invention. Theinvention's scope is, of course, defined in the language in which theappended claims are expressed.

1. An elongate medical device for performing medical procedures on apatient comprising: a first member having a distal end, an outersurface, and a first lumen, the first member having an elongatedconfiguration wherein the length of the first member is at least tentimes greater than the width of the first member; a second memberpositioned within the first member, the second member having a lumentherein; and a hood stop, the hood stop positioned within the firstmember, the hood stop having a distal region facing the distal end ofthe first member and a shoulder region, the shoulder region beingconfigured to limit the travel of at least the first member or thesecond member past the hood stop.
 2. The elongate medical device ofclaim 1, wherein the shoulder region of the hood stop is configured tolimit the travel of the first member past the hood stop when the hoodstop is held in position at a target site in a patient.
 3. The elongatemedical device of claim 1, wherein the shoulder region of the hood stopis configured to limit the travel of the second member past the hoodstop when the hood stop is held in position at a target site in apatient.
 4. The elongate medical device of claim 1, wherein the firstelongate member has a distally decreasing inside diameter that preventsthe hood stop from exiting the distal end of the first elongate member.5. The elongate medical device of claim 1 wherein the distal end of thefirst member has a piercing end.
 6. The elongate medical device of claim1 wherein the second elongate member is slidable within the firstelongate member.
 7. The elongate medical device of claim 1 wherein thelumen of the second elongate member contains a therapeutic.
 8. Theelongate medical device of claim 1 wherein the hood stop includes alumen therethrough.
 9. The elongate medical device of claim 8 whereinthe second elongate member is sized to slide through the lumen of thehood stop.
 10. The elongate medical device of claim 1 wherein the firstmember also contains a shoulder region, the shoulder region of the firstelongate member sized to mate with the shoulder region of the hood stop.11. The elongate medical device of claim 1 wherein the first elongatemember and the second elongate can both extend past the distal region ofthe hood stop when the hood stop is held in position at a target site ina patient.
 12. The elongate medical device of claim 1 wherein at leastthe first elongate member or the second elongate member contains a PMRtherapeutic.
 13. The elongate medical device of claim 1 wherein thefirst elongate member contains one or more injection holes at its distalend.